Ring rail tracking arrangement for ring spinning machines

ABSTRACT

A tracking arrangement for synchronizing the vertical movement of a working platform; for example, forming part of an automatic servicing tender for ring spinning machines, with the vertically reciprocating ring rail of the spinning machine including drive means for independently moving said platform, means for sensing the changing position of said ring rail, and servo control means responsive to said rail position sensing means to control said independent drive means to drive said platform to follow the movement of said rail.

United States Patent [191 Lesser [111 3,827,226 1 Aug. 6, 1974 RING RAIL TRACKING ARRANGEMENT FUR RING SPINNING MACHINES [75] Inventor: Eliyu Lesser, Worcester, Mass. [73] Assignee: Leesona Corporation, Warwick, R1.

22 Filed: Sept. 19,1973

21 App]. No.: 398,577

52 U.S.C1 57/341! 51 met DOlh 15/00 [58] Field of Search 57/1 R, 34 R, 52, 53, 54; 242/355 R, 35.6 E

[56] References Cited UNITED STATES PATENTS 3,373,551 3/1968 Gillono et a1. 57/34 R 3,664,109 5/1972 Escursell-Prat. 57/34 R 3,673,780 7/1972 Merck 57/34 R Primary Examiner-Donald E. Watkins Attorney, Agent, or FirmAlbert: P. Davis; Burnett W. Norton [57] ABSTRACT A tracking arrangement for synchronizing the vertical movement of a working platform; for example, forming part of an automatic servicing tender for ring spinning machines, with the vertically reciprocating ring rail of the spinning machine including drive means for independently moving said platform, means for sensing the changing position of said ring rail, and servo control means responsive to said rail position sensing means to control said independent drive means to drive said platform to follow the movement of said rail.

7 Claims, 5 Drawing Figures PATENTEUMIB 61974 311.827.2267

SHEET 1 BF 2 78 FIG]. 2 44 PAIENTEDMIB 61w 3.827.226

SHEET 2 OF 2 RING RAIL TRACKING ARRANGEMENT FOR RING SPINNING MACHINES This invention relates to a multi-position spinning machines, i.e., spinning machines equipped with automatically functioning, tending or servicing equipment capable to detecting the occurrence at positions along the machine of conditions requiring servicing, such as the completion of a fully wound bobbin of yarn or the interruption in the spinning operation, and of carrying out the necessary operations to restore that position to normal functioning, and is concerned more particularly with an arrangement for effectively synchronizing the movement of the operational devices of the tending equipment with the moving ring rail.

Traditionally, ring spinning machines or frames have been tended by manual labor in which a human operator observes a given number of spinning positions, determines when an abnormal condition occurs at a given position, e.g. when a bobbin has been fully wound or the flow of the yarn interrupted, and then removes the partially or fully wound bobbin as the case may be and threads up the roving onto a fresh empty bobbin in order to restore that position to normal working operation. Needless to say, the cost of manual labor for this purpose is considerable and, in recent times, textile equipment manufacturers have concentrated heavily on developing equipment that will perform in essentially an automatic fashion the manipulative operations required for servicing such spinning machines. Examples of patents covering such equipment developed by the assignee of the present application and of interest in relation to the present invention include US. Pat. Nos. 3,403,866, 3,688,486, 3,724,192 and 3,735,576.

In ring spinning machines, a ring rail extends along each side of the machine with spaced openings thereon through which extend the spindles which support the bobbins on which the spun yarn is wound. A circular tracklike ring surrounds each such opening and a small c-shaped traveller rides freely on this circular track with the advancing yarn passing through the traveller on the way to the bobbin on the spindle. The ring rail is reciprocated within fixed limits in the vertical direction and, in so doing, traverses the advancing strand along the length of the take up bobbin in order to produce a shaped package of spun yarn thereon.

The most complex phase of the threading up operation of a working position on a ring spinning machine is that of engaging the yarn in the traveller and since this operation must necessarily be performed without interrupting the reciprocating motion of the ring rail, it follows that automatic equipment designed to accomplish this threading operation must be capable of moving in close synchronism with the movement of the ring rail. To this end, the automatic tending equipment disclosed in the above-identified patents included a platform-like sub-carriage adapted to undergo independent vertical movement relative to the main carriage of the tender and mechanical or pneumatic devices needed for performing the threading up operation were mounted on this platform-like sub-carriage. A guiding track was provided along the forward edge of the ring rail itself and the sub-carriage was equipped with rollers directly engaging this guiding track. Hence, the sub-carriage was moved up and down in unitary fashion with the ring rail as the main carriage of the tender patrolled longitudinally along the side of the spinning frame, riding on additional tracks affixed to the frame for that purpose.

In conventional ring spinning macnines as employed in the textile field for many years, the ring rail is reciprocated through lifter rods acted upon by lifter cams which exerted a positive lifting action on the rods and then withdrew, allowing the rail and rods to move downwardly under their own weight. In the tending system described in the patents identified above, the utilization of a direct mechanical connection between the sub-carriage of the tender and the ring rail tended to interfere to a significant degree with the smooth reciprocating operation of the ring rail. Even though counter-balancing means was included in order to offset the weight of the sub-carriage and the mechanical devices carried thereon, the added inertia and frictional resistance was enough to affect the travel of the ring rail. Such interference disturbed the regular build up of the yarn windings in the yarn package and on occasion resulted in a breakage in the travelling yarn.

The object of the present invention is to provide an arrangement for controlling the vertical movement of a sub-carriage or working platform of an automatic tending system of the type in question in close synchronism with the vertical reciprocation of the spinning machine ring rail without disturbing the motion of the ring rail.

Another object of the invention is the provision of an automatic tending system in which the sub-carriage or working platform carrying the ring threading devices is maintained in an inoperative retracted position free of contact with the ring rail during the normal patrolling of the tender carriage, is brought from such retracted position to operative position when the tender carriage has halted at a spinning position requiring attention, is moved up and down vertically in precise synchronism with the ring rail with only the barest mechanical contact with the ring rail during the threading up operation, and is then returned to retracted position fully disengaged from the ring rail.

These and other objects will be more fully apparent from the following detailed description when read in conjunction with the appended drawings in which:

FIG. 1 is a view taken in substantially side elevation of one embodiment of the sub-carriage tracking arrangement of the present invention showing only fragments of the spinning machine and the main carriage of the servicing tender;

FIG. 2 is an enlarged detailed view of the tracking arrangement of the present invention, shown in transit from its retracted position to its operative position;

FIG. 3 is a detail view similar to FIG. 2 showing the tracking arrangement approaching the ring rail preparatory to taking its synchronized position;

FIG. 4 is a view similar to FIGS. 2 and 3 with the arrangement of the invention in operative position; and

FIG. 5 is a top plan view looking down on FIG. 4.

The present invention is most readily understood in terms of an improvement upon the apparatus of the patents identified above, especially U .S. Pat. No. 3,403,866, and the disclosure of the above-identified patents is expressly incorporated by reference in the present specification. In order to simplify this description, only enough of the prior machine will be referred to herein as is needed to give a context for understanding the present improvements. Thus, there can be seen in FIG. 1 only a fragment of the supporting frame of the conventional ring rail spinning machine indicated at 22 together with the spindle rail 24 which extends longitudinally and is seen in cross-section in this figure. Spindle rail 24 supports a plurality of vertically extending spindles 26 at spaced points therealong, the lower end of the spindles adjacent the top of the spindle rail 24 being formed as cylindrical whorl 28 for driving engagement with an endless driving belt not shown. A bobbin B seen in phantom in FIG. 1 is adapted to be lodged in place on the spindle 26. Afflxed to the base of the machine frame 22 is a set of tracks which are indicated diagrammatically at 30, 32 and in the embodiment depicted here constitute the supporting tracks for the travelling tender for servicing the spinning machine. For purposes of this description, in FIG. 1 is shown only a fragment of the travelling tender, which is generally designated S, including a portion of the floor 34 of the main carriageC with the flanged wheels 36, 38 projecting downwardly therefrom in riding engagement with the tracks 30, 32, respectively.

As disclosed in the patents identified above, the tender carriage is equipped with motive power means represented by a motor M for driving the same lengthwise along the tracks 30, 32 and means for observing when the tender carriage is oriented in functional relation to a spinning position on the frame at which a condition exists indicating the need for the services of the tender, such means being represented schematically by a tachometer T sensing when the driving motor M has stopped the carriage in proper registration with a given position. As mentioned already, one such condition is the completion at that position of a fully wound bobbin, necessitating the removal of that bobbin, the placement on the spindle in question of a fresh or empty bobbin and the threading up of the position to initiate winding on the new bobbin. Another such condition is a rupture or interruption in the flow of yarn at the position for any of a variety of reasons, requiring either that the end of the interrupted yarn be reunited with the trailing end from the partially wound package, or, alternatively, the removal of the partially wound bobbin, its replacement by an empty bobbin, and the re-initiation of the spinning operation with the new bobbin. The instrumentalities for detecting the occurrence of a condition suitable for servicing by the tender and for bringing the tender to a halt in a location appropriate for servicing that position are merely represented here by the housing H on sub-carriage 1 without further description. For an understanding of the details of these features, reference may be had to the specification of the above patents.

Extending vertically upwardly from the carriage floor 34 in spaced parallel relationship is a set of guiding posts 40 which serve to guide the movement in a vertical direction of the working platform or sub-carriage l. Spaced above the spindle rail 24 with apertures therein for penetration by each of the spindles 26 is a ring rail 42 which carries an annular ring 44 around each of the spindle apertures. A generally c-shaped traveller 46 rides on the upper flange of the ring 44 in engagement with the strand of yarn (not seen) to hold that yarn clear of the periphery of the bobbin B. The ring rail 42 is reciprocated vertically up and down through a limited path of travel by means of lifter rods 48 seen fragmentarily in FIG. 1 which are driven through lifter rod motion which is conventional in the art and not depicted here. As the rail is reciprocated vertically, yarn is traversed and distributed along the length of the take-up bobbin B to form a package of yarn windings on the bobbin as is well known in the art.

In accordance with the invention, the platform or subcarriage I is maintained in a lower retracted position indicated in phantom in FIG. 1, during the normal lengthwise patrolling action of carriage C and until the carriage is properly aligned with a spinning position requiring servicing, as indicated by the tachometer T. The platform or sub-carriage I is then moved to operative position and caused to follow the vertical reciprocating motion of ring rail 42. To move the platform I vertically, a double-acting fluid cylinder, such as an air cylinder 50 is arranged generally vertically on the carriage C with one end rigidly fastened to the carriage floor 34 and the free end of piston rod 51 pivoted to the platform I. Air under pressure is supplied or exhausted, as the case may be, from the opposite sides of cylinder 50 through corresponding accumulators or surge tanks 56, 58 which improve the dynamic stability of the system through the process of transient flow stabilization. The platform can be recessed as at 55 to receive the upper end of cylinder 50 if necessary for the platform to be retracted clear of the working limits of ring rail 42.

The flow of the pressurized fluid from a supply conduit 59 to and from the opposite ends of cylinder 50 is controlled by means of a servo valve 60 in conjunction with a 3-way main supply valve 62. During the normal patrolling operation of tender S, the main supply valve 62 delivers fluid from supply conduit 59 directly to line 54a, which is one of two lines communicating with tank 58 connected to the upper end of cylinder 50, and thus biases sub-carriage I to its lowermost retracted position. When the carriage C is properly aligned with a spinning position requiring servicing, tachometer T gives a signal which is transmitted to main valve 62 and connects through an actuating solenoid that valve to servo valve 60 through line 61 while disconnecting line 54a from supply conduit 59.

Servo valve 60 is of the 4-way type so as to alternately supply and exhaust pressurized fluid to and from two lines from the common input line 61 in accordance with the mechanical actuation of a valve core 64, as indicated schematically in FIG. 3. The lands 66 of valve core 64 are tapered as at 68 in order that the response of the servo valve may approach proportionality. The valve core projects to the right exteriorally of the body of valve 60 in the form of an operating button 70 and a compression spring 72 biases button 70 to the far right position (seen in FIG. 2). Thus, in its rest" position servo valve 60 supplies fluid to line 52 and thence through tank 56 to the lower side of cylinder 56 driving the piston rod 51 in an upward direction and forcing sub-carriage I upwardly at a controlled rate. Control of the rate of movement of carriage I upwardly may be achieved by an adustable flow control valve 53 in line 54.

Servo valve 60 is mounted on a bracket 74 upstanding from the sub-carriage I and which also carries certain other working components of the present arrangement. Principal among these is a feeler swing arm 76 and a servo actuating lever 78 which are connected through a lost-motion connection. The feeler swing arm 76 has the form of a roughly L-shaped plate which is pivoted at its lower end about a stub shaft 80 rigidly fastened on the supporting bracket 74 and having at its upper end a lateral extension 82 terminating at its extreme lower corner with a small feeler roller 84. Along the upper edge of swing arm 76 are two spaced-apart rigid pins 86 which provide a lost-motion connection between arm 76 and actuating lever 78. The latter is pivoted intermediate to its ends on stub shaft 80 for independent pivotal movement with its upper end extending freely between the spaced apart pins 86 on the swing arm 76 and its lower end terminating in an offset flange 88 for engagement with the face of the operating button 70.

In accordance with this invention, the feeler roller 84 and its swing arm 76 must be maintained in retracted position, that is in a position in which the arm is pivoted in a counter-clockwise direction to a sufficient extent as to be located clear of the path of ring rail 42 during initial upward movement of sub-carriage I. This retracted position is indicated in dotted lines in FIG. 2. When platform I has been lifted to a level such that the lateral extension 82 of arm 76 is situated above the level of the stop surface of the ring rail, the swing arm is pivoted in a clockwise direction to project it to operative position. The projection and retraction of the swing arm 76 is controlled by means of a small singleacting fluid cylinder, such as air cylinder 90, located above the servo'valve 60, the cylinder end being pivoted to bracket 74 at 91, and its piston rod 92 pivoted to the approximate midpoint of feeler swing arm 76 as at 93. Cylinder 90 is normally biased to retract rod 92 and pressurized fluid is supplied to extend rod 92 through a line 94 controlled by a solenoid valve 96. The latter valve is actuated in response to the arrival of the sub-carriage I in vertically aligned position with respect to the ring rail 42, such arrival being sensed by a flat V- shaped feeler finger lot) pivoted at its upper end to the reverse side of bracket 74 and projecting at its lower end into the path of the ring rail. Feeler finger 100 operates a microswitch 102 (see FIG. 5) which controls the operation of solenoid valve 96. When feeler finger we is contacted by the ring rail (see FIG. 3) as the platform I moves upwardly, it closes microswitch 102, energizing solenoid valve 96 to pressurize the cylinder 98. The piston rod 92 is extended in the rightward direction in H6. 2, pivoting swing arm 76 in a clockwise direction to position the feeler roller 84 in overhanging relation to the top surface of ring rail 42, as shown in FIG. 3.

As feeler swing arm 76 moves to projected operative position, the outer of the two spaced pins 86 carried thereon contacts the upper end of servo actuating arm 78, pivoting that arm to the position seen in FIG. 3. This depresses the operating button 70 of servo valve 60 to the left, because of the engagement of the offset flange 88 at the lower end of actuating arm 78, shifts the valve core 64 well past its neutral position and re verses the flow of pressurized fluids through servo valve 60. Thus, the air cylinder driving platform I now becomes pressurized at its upper end while the lower end is exhausted and the operating direction of the platform I thus is reversed and the sub-carriage starts to move downward.

At this point, it will be recalled, feeler swing arm 76 is still in its fully projected position with the feeler roller 84 in over-hanging relation to the top surface of ring rail 42 and as sub-carriage I drops roller 84 will therefore shortly make contact with the top rail surface.

Continued downward travel of sub-carriage] after engagement of feeler roller 84 on the ring rail forces the swing arm 76 to pivot counter clockwise. As the follower arm pivots in this fashion, servo actuating lever 78follows that pivotal motion because of the compressive force of spring 72 acting on actuating arm 78 through button 70. This shifts the valve core rightwardly to retard the rate of downward movement of sub-carriage I until that rate becomes synchronized with the downward movement of ring rail 42. When, on the other hand, the ring rail reaches the lower limit of its travel and begins its upward movement, the change in direction is sensed by the feeler roller 84 and transmitted to the swing arm 76 and thence to servo actuating arm 78. The core 64 of servo-valve 60 therefore moves through and slightly past neutral position so as to reverse the action of the cylinder #0, driving the platform I in the upward direction at a rate closely consistent with the upward movement of the ring rail. This tracking relationship continues in both directions as long as needed for the serving operation to be completed.

The size of the small pressurized cylinder 90 and the pressurization of the fluid supplied thereto are so selected as to exert upon swing arm 76 a force that is sufficiently great to approximately balance the force exerted on the servo valve operating button by compression spring 72. With these two forces in substantially balanced condition, only a very small amount of force need to be applied to the feeler roller 84 by the ring rail in order to bring about a corresponding response in the controlled position of servo valve 60 and thus in the direction and rate of movement of the drive cylinder 50.

When the servicing functions of the carriage C have been carried out at the given spinning position, a signal is generated by means not shown to override microswitch 102, de-energize solenoid valve 96 and exhaust cylinder 90, thus retracting feeler swing arm 76 and feeler roller 84 away from the ring rail, on the one hand, and change main control valve 62 to disconnect servo valve 60 and connect supply conduit 59, driving sub-carriage I positively downwardly away from the ring rail to its retracted inoperation position, on the other hand.

The utilization of a servo actuating lever 78 separate from feeler swing arm 76 in the above embodiment is due to spacial limitations arising from the requirement that the feeler roller be movable to and from projected and retracted position without coincidentally displacing other components into the path of the moving ring rail. In other embodiments with less stringent space limitations, a single integral lever could readily be devised.

Some modifications and variations in the arrangement of the invention have been already suggested in the course of the foregoing description and others will be readily suggested to the skilled worker in the art without departing from the spirit of the present improvement.

What is claimed is:

1. A tracking arrangement for the vertically reciprocating ring rail of a textile ring spinning machine, said arrangement comprising a vertically movable platform to be driven in synchronism with said ring rail, drive means for independently moving said platform, means for sensing the changing position of said ring rail, and

servo control means responsive to said rail position sensing means to control said independent drive means to drive said platform to follow the movement of said rail.

2. The arrangement of claim 1 including a sensing arm biased into lightly touching contact with a vertically moving edge on said ring rail, said arm being pivoted on said platform for limited pivotal movement to and fro in response to the direction of travel of said rail, and lever means transmitting said limited pivotal movement of said arm to said servo control means.

3. The arrangement of claim 1 wherein said platform drive means is a double-acting pressurized fluid motor and said servo control means is a four-way servo valve for variably controlling the supply of said fluid to the opposite sides of said fluid motor.

4. The arrangement of claim 1 wherein said sensing means is adapted to contact a horizontal surface on said ring rail and including means supporting said sensing means on said platform for generally lateral movement between a retracted position clear of the path of said rail and a projected operative position contacting said rail surface, means normally effective to maintain said sensing means supporting means in said retracted position and operable to move the same to said projected position, and feeler means for detecting when said platform and rail in a predetermined adjacent vertical relationship to operate said last-named means.

5. In an automatic tending system for multi-station textile ring spinning machines comprising a tender carriage adapted to patrol along at least one side of said machine, detect the existence at a given station of said machine of a condition requiring servicing, position itself in operative relation to such position and perform operative functions to service said position, in which said carriage includes a sub-carriage mounted for independent vertical reciprocating movement on said carriage and supporting instrumentalities for performing certain of said operative functions: in combination, an arrangement for synchronizing the reciprocation of said sub-carriage with that of the ring rail of the spinning machine comprising drive means for independently moving said sub-carriage, means for sensing the changing position of said ring rail, and servo control means responsive to said rail position sensing means to control said independent drive means to follow the movement of said rail.

6. The tending system of claim 5 during normal patrolling of said carriage wherein said sub-carriage is maintained in a position remote from said ring rail with said sensing means and servo control means inoperative and including means responsive to the positioning of the carriage in operative position to activate said servo control means to bring said sub-carriage to operative position adjacent said ring rail.

7. The tending system of claim 6 wherein said sensing means is adapted to contact a horizontal surface on said ring rail and including means supporting said sensing means on said sub-carriage for generally lateral movement between the retracted position clear of the path of said rail and a projected operative position contacting said surface, means normally effective to maintain said sensing means supporting means in said retracted position and operable to move the same to said projected position, feeler means for detecting when said sub-carriage and rail in a predetermined adjacent vertical relationship to operate said last-named means. a 

1. A tracking arrangement for the vertically reciprocating ring rail of a textile ring spinning machine, said arrangement comprising a vertically movable platform to be driven in synchronism with said ring rail, drive means for independently moving said platform, means for sensing the changing position of said ring rail, and servo control means responsive to said rail position sensing means to control said independent drive means to drive said platform to follow the movement of said rail.
 2. The arrangement of claim 1 including a sensing arm biased into lightly touching contact with a vertically moving edge on said ring rail, said arm being pivoted on said platform for limited pivotal movement to and fro in response to the direction of travel of said rail, and lever means transmitting said limited pivotal movement of said arm to said servo control means.
 3. The arrangement of claim 1 wherein said platform drive means is a double-acting pressurized fluid motor and said servo control means is a four-way servo valve for variably controlling the supply of said fluid to the opposite sides of said fluid motor.
 4. The arrangement of claim 1 wherein said sensing means is adapted to contact a horizontal surface on said ring rail and including means supporting said sensing means on said platform for generally lateral movement between a retracted position clear of the path of said rail and a projected operative position contacting said rail surface, means normally effective to maintain said sensing means supporting means in said retracted position and operable to move the same to said projected position, and feeler means for detecting when said platform and rail in a predetermined adjacent vertical relationship to operate said last-named means.
 5. In an automatic tending system for multi-station textile ring spinning machines comprising a tender carriage adapted to patrol along at least one side of said machine, detect the existence at a given station of said machine of a condition requiring servicing, position itself in operative relation to such position and perform operative functions to service said position, in which said carriage includes a sub-carriage mounted for independent vertical reciprocating movement on said carriage and supporting instrumentalities for performing certain Of said operative functions: in combination, an arrangement for synchronizing the reciprocation of said sub-carriage with that of the ring rail of the spinning machine comprising drive means for independently moving said sub-carriage, means for sensing the changing position of said ring rail, and servo control means responsive to said rail position sensing means to control said independent drive means to follow the movement of said rail.
 6. The tending system of claim 5 during normal patrolling of said carriage wherein said sub-carriage is maintained in a position remote from said ring rail with said sensing means and servo control means inoperative and including means responsive to the positioning of the carriage in operative position to activate said servo control means to bring said sub-carriage to operative position adjacent said ring rail.
 7. The tending system of claim 6 wherein said sensing means is adapted to contact a horizontal surface on said ring rail and including means supporting said sensing means on said sub-carriage for generally lateral movement between the retracted position clear of the path of said rail and a projected operative position contacting said surface, means normally effective to maintain said sensing means supporting means in said retracted position and operable to move the same to said projected position, feeler means for detecting when said sub-carriage and rail in a predetermined adjacent vertical relationship to operate said last-named means. 